Screen printing machine with magnetic work support

ABSTRACT

A device for the treatment, particularly for the printing, of flat-shaped material which is moved between two working elements exerting a pressure upon each other. One of the working elements, particularly the printing support of a printing form body, contains a magnet body consisting of a plurality of electromagnets whose magnet cores are arranged in one or more lines having preferably axes perpendicular to the flat shaped material to be treated. The magnet cores project into a stable support body directed to the flat-shaped material to be treated, covered, if the case may be, by a thin casing wherein the stable support body is provided with a recess or perforation passing through the line of magnet cores in whose zone the pole faces of the magnet cores end at a distance from the surface of the support body directed to the material to be treated.

United States Patent Inventor Appl. No.

Filed Patented Assignee Priority SCREEN PRINTING MACHINE WITH MAGNETICWORK SUPPORT 1 Claim, 4 Drawing Figs.

U.S. Cl.

Int. Cl B41! 15/08,

Field o1Search..

120, l24, 123; 1 181B & S; 107/114, 407

References Cited UNITED STATES PATENTS 7/1898 Rouse .4

Peter Zimmer 6330 Engelhardstrasse, Kul'stein Willibald Ruckl, Tirol,both of, Austria 755.543

Aug. 27, 1968 Aug. 3, 1971 said Peter Zimmer, Kufstein, Austria, by saidWillibald Ruck] Aug. 28, 1967, Sept. 4, 1967 Austria A7874/67 andA8065/67 B41fl5/18 101/119,

Primary Examiner- Robert E. Pulfrey Assistant Examiner-J. Reed FisherAnomey-Wenderoth, Lind & Ponack ABSTRACT: A device for the treatment,particularly for the printing, of flat-shaped material which is movedbetween two working elements exerting a pressure upon each other. One ofthe working elements, particularly the printing support of a printingform body, contains a magnet body consisting of a plurality ofelectromagnets whose magnet cores are arranged in one or more lineshaving preferably axes perpendicular to the flat shaped material to betreated. The magnet cores project into a stable support body directed tothe flat-shaped material to be treated, covered, if the case may be, bya thin casing wherein the stable support body is provided with a recessor perforation passing through the line of magnet cores in whose zonethe pole faces of the magnet cores end at a distance from the surface ofthe support body directed to the material to be treated.

PATENTED AUG 3197! mvmoas PETER ZIMME WILLIBALD RUCKL ATTORNEYS SCREENPRINTING MACHINE WITH MAGNETIC WORK SUPPORT This invention relates to adevice for the treatment, especiallv for the printing, of flat-shapedmaterial which is moved between two working elements exerting a pressureupon each other. one of said working elements, especially the printingsupport of a printing form body containing a magnet body, said magnetbody consisting of a plurality of electromagnets whose magnet cores arearranged in one or more lines and have preferably axes perpendicular tothe flat-shaped material to be treated. said magnet cores projectinginto a stable support body directed to the flat-shaped material to betreated, and, if the case may be, being covered by a thin casing.

Such a device is known e.g. in rotary screen printing machines, theroller or doctor blade provided inside each cylinder screen consistingof magnetizable material and being attracted by the magnet body arrangedin the printing support.

The heat development unavoidable during the operation of the differentelectromagnets of the magnet body results in a certain length extensionof the magnet cores, thus causing the pole faces to show up from thestable support body of the printing support. Thus the originally smoothsurface of the printing support is disturbed, and this even, if a thincasing, e.g a sliding sheet, is provided over the stable supporting faceand the magnet cores. The thin casing is buckled out by the lengthextension of the magnet cores. A further result of the magnet coresprojecting over the surface of the stable support body or of thebucklings of the casing are striplike irregularities in printing, thematerial to be printed absorbing more color between the magnet coresthan in the strongly pressed zones over the magnet cores.

This shortcoming is avoided according to the invention in that thestable support body is provided with a recess or perforation passingover the line of magnet cores in whose zone the pole faces of the magnetcores end in a distance from the surface of the support body directed tothe material to be reated Thus the pole faces of the magnet cores aregiven a distance from the printing zone of the material to be printed.In this zone alterations of length of the magnet cores can take placewhich do not show disadvantageous effects. The zones of the support bodylying in the direction of passage of the material to be printed in frontof and behind the recess or perforation of the support body, provide forthe necessary firm support of the material to be printed in the printingzone Emb--diments of the invention are hereinafter described more indetail without being limited to them:

FIG I shows a diagram of a screen station of a rotary screen printingmachine.

FIG. 2 shows the printing support of the screen station (without slidingsheet).

F IGv 3 is a section through the screen station (along A-B of FIGv 2).

FIG. 4 shows an analogous section of an embodiment according to FIGS. 1to 3.

In the embodiment according to FIGS. I to 3, a roller 2 of magnetizablematerial, eg of steel, is arranged inside the screen cylinder 1 of arotary screen printing machine, said roller pressing the screen cylinder1 onto the material to be printed 3 and applying the color through thescreen openings of the screen cylinder 1 onto the material to be printedwhile rolling off the screen inwall. The flat-shaped material to beprinted 3, e.g. textile material, is transported by the blanket 4.

Under the blanket 4, opposite the screen cylinder 1, a magnet bar isarranged as printing support by which the roller 2 is attracted andwhich consists of a plurality of electromagnets 5 whose cylindricalmagnet cores 6 project into a stable support body 7. The support body 7is covered by a thin sliding sheet 8. It supports the material 3 withthe blanket 4.

Along the line of magnet cores 6 of the electromagnets 5 the supportbody 7 is provided with a groove 9. The pole faces 10 of the magnetcores 6 end in the basis of the groove 9. Therefore the latter have adistance from the surface of the support body 7 which allows a harmlessclearance of motion of the magnet cores 6 owing to the heating duringthe current passage through the windings of the electromagnets 5. Evenif the pole faces 10 show up from the basis of the groove 9, the slidingsheet 8 and the blanket 4 moved over the sliding sheet 8 remains smooth.The pressure given to the material 3 by the magnetic attraction of theroller 2, is regular over the whole width so that a disadvantageousstrip formation during the printing operation is avoided. Besides, thesliding sheet 8 can bend through like a spring in the free space formedby the groove 9; thus, despite of the rigid hard roller 2, an elasticpressure is obtained instead of the usually hard pressure, which has afavorable effect on the printing quality.

The function as described remains the same if the sliding sheet 8 islacking. In this case, the blanket 4 directly springs into the spaceformed by the groove 9. Said space can be filled up by a material of asolid state, but of compressible and --up to a certain degree elasticbehavior (e.g. felt, elastomere, foam material). This material may alsoserve as protection against corrosion of the magnet cores consisting ofsoft iron and very sensitive to corrosion. A covering can also beapplied to the pole faces as protection against corrosion.

FIG. 4 also illustrates a screen station of a rotary screen printingmachine. Inside the screen cylinder 1, the roller 2 of magnetizablematerial is contained, said roller pressing the screen cylinder I ontothe material to be printed 3 and applying the color through the screenopenings of the screen cylinder 1 onto the material to be printed 3during rolling off the screen inwall. The material to be printed 3 istransported by the blanket 4.

According to FIG 4 the printing support has the form of a roller whosecasing 8' rotates around a stationary carrier This carrier, like themagnet bar according to FIGS. 1 to 3, is provided with a plurality ofelectromagnets 5 having magnet cores 6. The magnet cores also projectinto a stable support body 7' whose surface IS cylindrical. Like inFIGS. 1 to 3, the support body 7 is provided with a groove in whosebasis the pole faces 10 of the magnet cores 6 end. As to the function ofthis groove. we refer to the explanations of the description of FIGS. 1to 3.

The embodiments as shown and described refer to the application of themeasure according to the invention to screen printing machines providedwith rotary screens. However. the invention is not limited to thisapplication. The measure according to the invention can also be appliedto magnet bars or magnet rollers for flat screen printing machines.

We claim:

1. A device for the printing of flat-shaped material comprising twoworking elements exerting a pressure upon one another between which saidmaterial is passed, one of said working elements forming a printingsupport containing a magnet body having a plurality of electromagnetshaving magnet cores, said magnet cores being arranged in series withtheir axes perpendicular to said flat-shaped material, a stable supportbody turned toward said flat-shaped material into which said magnetcores project, the other of said working elements forming a squeegeearranged in and engaging in a printing screen said printing screencontacting said material opposite said support body, said printingscreen contacting said material opposite said support body, said stablesupport body having a recess extending over said series of magnet coresso that the pole faces of said magnet cores terminate at a distance fromthe surface of said support body turned toward said material to beprinted, and said surface of the stable support body turned toward thematerial to be printed being provided with a thin sheet cover capable ofbeing deflected into said recess of said stable support body.

1. A device for the printing of flat-shaped material comprising twoworking elements exerting a pressure upon one another between which saidmaterial is passed, one of said working elements forming a printingsupport containing a magnet body having a plurality of electromagnetshaving magnet cores, said magnet cores being arranged in series withtheir axes perpendicular to said flat-shaped material, a stable supportbody turned toward said flat-shaped material into which said magnetcores project, the other of said working elements forming a squeegeearranged in and engaging in a printing screen said printing screencontacting said material opposite said support body, said printingscreen contacting said material opposite said support body, said stablesupport body having a recess extending over said series of magnet coresso that the pole faces of said magnet cores terminate at a distance fromthe surface of said support body turned toward said material to beprinted, and said surface of the stable support body turned toward thematerial to be printed being provided with a thin sheet cover capable ofbeing deflected into said recess of said stable support body.